Process of producing calcium metaphosphate and ammonia.



UNITED STATES PATENT onrion.

FREDERICK W. FRERICHS, OF ST. LOUIS, MISSOURI.

PROCESS OF PRODUCING CALCIUM METAPHOSPHATE AND AMMONIA.

No Drawing.

Specification of Letters Patent.

Application filed August 20, 1910. Serial No. 578,226.

- Patented Aug. 29, 1911.

To all whom if may concern:

Be it known that I, FREDERICK W. FRE- RICI-IS, a citizen of the United States, residing at the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Processes of Producing Calcium Metaphosphate and Ammonia; and I do hereby declare the following to be a full, clear, and exact description of the inventlon, such as will enable others skilled in the art to which it appertains to make and use the same.

In the manufacture of fertilizer material, calcium phosphate is treated with sulfuric acid to roduce a mixture of valuable calcium acid phosphate and gypsum which is an admixture of no value in conformity with:

Formula A.

The reaction takes place by simply mixing the materials at ordinary temperature.

In the production of ammonia from ammonium sulfate and caustic lime, ammonia is liberated and the sulfuric acid combined with the lime to make gypsum which is valueless and goes to waste by:

' Formula B.

2NH +CaSO 2H O The reaction is carried out by mixing the materials with a large excess of water and distilling off the ammonia. v

The process which forms the subject matter of this application combines the two reactions represented by Formulae A and B producing from calcium phosphate and ammonium sulfate 'a mixture of calcium acid phosphate and gypsum the same as obtained inFOrmula A and free ammonia gas as obtained in Formula B theoretically by the following:

Formula 0'.

It is evident thatin the reaction represented by Formula C the same result is obtained as in the two reactions represented by Formulae A and B with the exception that all the sulfuric acid is saved monium sulfate at 250 0., ammonia com-.

mences to be liberated. By increasing the temperature radually to 343 C. (650 F.) about'one-ha f of the ammonia present in the mixture is set free and the second half of the ammonia can be liberated by gradually increasing the temperature to 500 0., a number of reactions taking place which may be represented by the following:

Formula D.

(P0,) 08. IZNILHSC) 2NII (POJ-I 03. ZCaSO 4NI-I (1 09 08. 202L80 INT-I ZH O At the temperature required for the reaction ammonia, and water escape and a mixture of calcium metaphosphate and calcium sulfate remains in the retort. By treating this mixture with water, a mixture of calcium acid phosphate and calcium sulfate is obtained by well known reactions according to:

Formula E.

This series of reactions therefore produces the same fertilizer material as Formula A and the valuable part of the products of Formula B, viz., ammonia, omitting the waste products of Formula B and saving the costly sulfuric acid and lime used by Formulae A and B.

It is not necessary to carry the reactions indicated by Formulae C and D to completion since a small proportion of ammonium sulfate which may escape decomposition retains full value in the resulting fertilizer material:

An excess of phosphate calcium or the application of a vacuum during the roasting process accelerates the reactions.

In Formulae A, C, and E water enters into the reaction to combine with acid phosphate calcium and sulfate calcium as Water perature from normal to a temperature in excess of 650 F. until the major portion of the ammonia content has been liberated and the major portion of the calcium phos- I phate has been converted into calcium metaphosphate.

In testimony whereof I affixed my signa ture in presence of two Witnesses.

. FREDERICK W. FRERICHS.

Witnesses:

L. L. MORRILL, NANNIE MEEM. 

